Neil Warnock has been keen to keep his first team together but has allowed Simon Francis, Alan Wright and Dominic Roma go on the transfer list.
Other players, including former Barnsley and Crystal Palace striker Bruce Dyer have been released on a free transfer, Dyer played just five times for the Blades, scoring on his debut in the 1-1 home draw with Reading.
Other players released include; Gary Mulligan, Sharu Naraji, Kyle Nix, San Lee, Jamie Green and Adrian Harper.
Meanwhile League One outfit Gillingham have completed the signing of former Wolves striker Gary Mulligan from Sheffield United as well as former Owls frontman Guylain Ndumbu-Nsungu from Cardiff City.
Mulligan, one of ten released by the Blades signed last season from Wolverhampton Wanderers but has made only two outings for United, these coming in the League Cup victories over Boston United and Shrewsbury Town.
He had successful loan spells at Port Vale and Gillingham before being released by the Premier League newcomers.